The invention belongs to the technical field of composite metal pipe centrifugal casting, and particularly relates to a control method for inner layer stress of a bimetal centrifugal casting composite pipe. According to the method, centrifugal casting of an outer layer and an inner layer is conducted to the interior of a die barrel rotating at a high speed, then, a large-power air blower continuously blows cold air into the die barrel, temperature reducing and cooling of the metal of the inner layer are accelerated, then, the rotation speed of the die barrel is gradually reduced till the die barrel stops, blowing in of the cold air is kept in the period, and air blowing is stopped after the composite pipe is cooled to the room temperature. According to the method, the metal of the inner layer of the centrifugal casting composite pipe can be cooled earlier than cooling of the metal of the outer layer, and the composite pipe with the metal of the inner layer subjected to press stress and the metal of the outer layer subjected to pull stress is prepared. Due to the fact that the metal of the inner layer of the centrifugal casting composite pipe is composed of abrasion resisting metal high in brittleness and harness, the metal of the inner layer bears the press stress, stress cracks are prevented from being formed in the metal of the inner layer, and accordingly the yield and the service life of the centrifugal casting composite pipe are improved.